The jury and the defense of insanity.

Juries given the M’Naghten definition of insanity much less likely to hang or acquit by reason of insanity than juries receiving no definition or Durham definition. Form of expert testimony had little impact on jury verdicts in the 68 incest trials; fate of defendant in event of not guilty by reason of insanity had no impact on verdicts in the 30 burglary cases.